NC Chemistry Pretest

Front

What happens to the atomic mass and atomic number when a gamma ray is emitted by an element?

Back

The atomic mass stays the same and the atomic number stays the same.

Front

Colligative properties depend on the _________ of the solute but not the __________ of the solute.

Back

Colligative properties depend on the concentration of the solute but not the identity of the solute.

Front

Which diagram has the highest boiling point?

Back

Diagram 5 has the highest boiling point.

Front

What is the difference between a chemical change and a physical change?

Back

Chemical changes create new substances.

Front

What completes the radioactive decay equation: 174_79Au => 170_77Ir + ?

Back

Alpha particle.

Front

Define atomic mass.

Back

The weighted average mass of an element's isotopes, measured in atomic mass units (amu).

Front

What is the definition of a chemical change?

Back

A process that results in the formation of new chemical substances.

Front

What is a physical change?

Back

A change that affects one or more physical properties of a substance without altering its chemical composition.

Front

What are colligative properties?

Back

Properties that depend on the number of solute particles in a solution, not their identity.

Front

What is the significance of the atomic number?

Back

The atomic number determines the element's identity and the number of protons in the nucleus.